Depends on what else you hope to use it for. If just for casual games, pretty much any device will probably work for you. The apps depend on the device type you get. I use SCIDontheGO on my Android tablet. It has some issues but it is free and I can work around its quirks.
If you are asking about rated play, the answers are different as there are only 3 devices officially supported/allowed for USCF rated play (Monroi, PlyCounter, and eNotate, I think, on a specific Dell handheld model).
Do I need something like ChessBase to study certain openings or games? Aren't electronic versions of magazines or periodicals necessary to take their PGN data and use on the handheld?
I will have to let someone else answer that. I don't currently use anything like that.
Well i own android devixe so im going tell my side.. Chessbase online is great apps to view pgn annotated games and u have access to all the games databse which is 7.5 millions games..and more new games to come.. There are serveral freee pgn viewer apps but i jus buy chessbase for android which cost 14 bucks.... Scid on the good is freee.. U can also get games from twic for free.. And u can get stockfosh as an engine... Then ur pretty set.. I read chess book on my samsung 8.4 pro tablet.. Pgn book
Pdf book req too much work u have to carry the board or use app like chess study... So pgn book from everyman are a plus , i think everyman have a freee pdf veiwer apps called e viewer .. i like the navigation of pgn master so i use that to read pgn book,. Chessbase book must be converted to pgn to be able to view on android... and download droid fish to analysis a game its freee
Monroi, PlyCounter are ok to used in OTB tournament play. eNotate can no longer be used in OTB tournaments.
Monroi, PlyCounter are ok to used in OTB tournament play. eNotate can no longer be used in OTB tournaments.
Do you have a reference for that? The only official notification still has it listed (http://archive.uschess.org/ratings/electronicscoresheet.pdf) and the US Class Championship e-mail I received from the USCF 3 days ago has the following (I know it's ran by an affiliate but is a National US Chess official event):
ELECTRONIC NOTATION DEVICES
There are three electronic chess notation devices which are approved for and allowed in a USCF-rated tournament: the Monroi, the e-Notate PDA, and the Plycount. You may use any one of these devices, but the device must remain on top of the table at all times (you may not hold it under the table in your lap or under the tablecloth, and the device cannot leave the tournament hall while your game is still ongoing). The tournament director has the right to request to see your notation device at any time before, during or after your game.
Monroi, PlyCounter are ok to used in OTB tournament play. eNotate can no longer be used in OTB tournaments.
Do you have a reference for that? The only official notification still has it listed (http://archive.uschess.org/ratings/electronicscoresheet.pdf) and the US Class Championship e-mail I received from the USCF 3 days ago has the following (I know it's ran by an affiliate but is a National US Chess official event):
ELECTRONIC NOTATION DEVICES
There are three electronic chess notation devices which are approved for and allowed in a USCF-rated tournament: the Monroi, the e-Notate PDA, and the Plycount. You may use any one of these devices, but the device must remain on top of the table at all times (you may not hold it under the table in your lap or under the tablecloth, and the device cannot leave the tournament hall while your game is still ongoing). The tournament director has the right to request to see your notation device at any time before, during or after your game.
I stand corrected. Apparently it is some TD's that take issue with enotate. What i was told appears to be incorrect...my apologies.
Chessbase online can view pgn files... move able chess book/ magazine are in pgn formate... pdf book and magazine doesnt have moveable pieces,,,
Chessbaseonline req a data connection to seee the games,,, i tether the data from my smart phone,, alot of freee pgn vewer apps,, pic the one that fit ur taste,,,
I stand corrected. Apparently it is some TD's that take issue with enotate. What i was told appears to be incorrect...my apologies.
No problem. I just wanted to check. I'm a TD and it is always possible that I missed a notification somewhere. 
400 views in 4 days is great but I need more help on these subjects, please, since only 12 have commented. You can load a whole series of games, PGNs, into a device and study them sequentially? I'm not up on this stuff, have the Everyman book on its way but since it is from 2004 or so, I need your help.
What exactly do you want to do?
Do you want a database app?
Do you want an app that has interactive books?
Do you want an app that plays chess against you?
Do you want an app so you can play your friends on the internet either live or correspondence style?
Do you want an app to teach you openings?
Do you want an app with tactics problems?
Do you want an endgame app?
If you tell us what you want to do we could then better tell you what you need to get to do that.
I'd like something I can input PGN data from elsewhere, a database I can search for openings or whole games. If I got a book that had PGNs, electronic or otherwise maybe, can I scan them into the app? I'm at the edge of what I do know, but I need the handheld device also to put the app on. Can I get by with the capabilities of a Fritz or the like program? I don't think I want to buy the app plus the device and a ChessBase program at the same time.
Thank you guardianx9 for your helpful comments. Other than that, the conversation got sidetracked to tournament play and I want this for personal use.
For a database I use ChessBase Online. There is a ChessBase Viewer App that has this option.
I am not aware of any app that allows you to scan a book into.
There are a few apps that allow you to download an interactive book. Some of the apps are for one company or publisher only. You will need more than one app for this. But they are all free apps. Of course you have to pay for the book, usually through the app.
I use a Shredder app. It allows me to input game moves and then save those games. It also has an option to email those games, in pgn format. It also gives you a game against the Shredder engine. It has tactics problems as well.
If I want to upload pgn games, there are a couple of apps that allow you to upload them into that app and view the games. ChessBase Viewer is one. There are a few others, but I don't use them for this so I don't remember which ones work.
That's the kind of help I need, thanks. Do you cut and paste PGN to "input game moves" and to "upload them"?
I did download some short games from this site. It required Chess Informant Expert and I only had the Lite version, so was not able to look at those games. I got the $5 book Chess Software Users Guide from the USCF Bookstore and he discusses creating his own sub-databases from about 6 different source databases, some of which are free. I think you either pay to use ChessBase or buy an older version for cheaper and make do with that. Not sure about what tablet or device to get as I am aiming for an armchair type of approach rather than desk sitting and using my desktop. You have to remove duplicate games (there's an app for that) from the final database you want to study but these may still contain just a diff. spelling of an opponent, etc. so some duplicates will still remain. It seems complex at this point. I got a free trial membership of ChessBase but it does not seem like much; game playing seems more involved and not many other features are free.
If you're serious about wanting to improve and chess is going to be a long-term hobby then I recommend buying ChessBase 13. it's around $150 I think for the software and a big database that comes with it (mine has around 6.1 million games), but it's really nice and convenient, because not only can you explore games and openings, you can create your own files with your own games, or own opening files. It helps alot.
Being new to chess apps and not having a smartphone, what device would be best to get, what app to use and how exactly do you input the PGN data? Any comments/help or advice on any or all of these would be appreciated.