The quick recommendation: Magnify Reader is simplest but bare, Magnifier by Person has the best combination of features and App Town’s Magnifier is also good.
The longer answer:
Modern smart phones have excellent cameras and with the right app are a real, practical alternative to dedicated electronic magnifiers for enlarging printed text and making small items easier to see. Here is a roundup of some of the best, free options I’ve come across. The main features I was looking for were:
– Ability to start in magnified view (otherwise you might as well use the default camera app).
– Magnified view takes up as much of the screen as possible.
– Easy ability to change zoom level, focus and toggle camera light on and off.
– The ability to freeze an image was a desirable bonus.
– The ability to invert colours was also a desirable bonus.
Firstly as a control, the Standard Camera App. I used the camera app from the Galaxy Note 2. Other device’s camera apps may be quite different. The view takes up about 75% and starts unmagnified, you can pinch zoom in and touch to focus. You can freeze (take a photo) and use effects to change the colour, however you can’t turn the light ‘on’ except as a flash when actually taking a photo.
Magnifier (Magnifying Glass) by Person
The view takes up virtually the whole screen; there is a small semi-opaque rectangle in the bottom right corner with the word “Menu” which brings up the options (Freeze, colour effects, light toggle). View starts magnified and you can pinch zoom in and out, tap to re-focus and double tap to toggle light. Pinch zoom can be slow to respond.
Magnifier by App Town
The view takes up about 90% of the screen. There are three controls at the bottom of the screen: a button to toggle light, a slider for magnification level and a button to refocus. View starts magnified and adjusting options (via controls – no gestures) is more responsive than previous app. No colour options or image freeze.
Magnify Reader by Mlinell
The view takes up the entire screen with no controls. The app starts at minimal (~1.25x magnification and you can swipe to the top of the phone zoom in and to the bottom zoom out. Tap to focus and double tap to toggle the light.
Old Person App by Third Layer
While I find the name a bit insulting, the app is relatively straight forward. It has three big buttons at the bottom “Magnifier”, “Light” and “Notepad” and they toggle those three things. The view takes up about 75% of the screen but the app starts with instructions and you then press the magnifier to go into that mode. There are no adjustment options but it is at maximum zoom and automatically refocuses as needed.
Other apps looked at:
Andreader Magnifier / Reader by Peter Glen (Uses 100% of the screen, pinch zoom and tap to focus however view is sideways and skewed and there is no way of turning the light off). https://play.google.com/store/apps/details?id=com.peterglen.andreader
Digital Magnifier by Appsnack – (Starts unmagnified; view is distorted and only takes up 80% of screen). https://play.google.com/store/apps/details?id=appsnack.dm
GrandMa’s Magnifier (App name in Chinese text, icon is pink magnifier) by JEJun – (No focus or magnification options, view is about 1.25x). https://play.google.com/store/apps/details?id=com.jun.scale
Handy Magnifying Glass by Darkstar – (Trial version is unusable with the view covered in writing. Even full version appears to be an image of a magnifying glass with only the circle of the magnifying glass showing a magnified view). https://play.google.com/store/apps/details?id=com.simplyusefulapps.android.handymagnifier.freetrial
Hugo’s Lupe Magnifier by Bend Schwarzmann – (No focus ability and zoom adjusted in small steps by volume keys). https://play.google.com/store/apps/details?id=com.emmo.lupe.gui
Magnifier and Mirror by Dong – (View only takes up about 60% of screen, is easy to rotate and starts unmagnified. Does have a mirror). https://play.google.com/store/apps/details?id=com.mnm
Magnifying Glass by David Parry – (View only takes up about 50% of the view and the buttons to control magnification and focus are quite small). https://play.google.com/store/apps/details?id=com.davidparry.magnifying
As with many types of apps, there are a lot of options available, many of which contain ads or other intrusive software, and even of the dozen I looked at, only a third really stood out. Person’s app has the most features, Old Person app is the simplest, Magnify Reader has the cleanest screen and App Town’s magnifier has a balance of visible on screen controls which don’t take up too much room.