I'm looking for a generic Android OS phone for testing apps. Is there a standard or will I need to purchase a couple of devices?
3 Answers
3I can't imagine there being a 'standard' because each vendor has its own 'flavor' of Android, and what version they care to support. Best bet is to get more devices. If you can't borrow, check places like Craigs List for people upgrading, you can post that you're looking for used phones there too.
you should bye a Nexus One ( if you want to make app for all High End + Medium End devices ) but its little outdated , try getting a Snapdragon Device because most phone uses that , if you not look to current change of Tegra . Well it depend on what majority of device you wanna make the app for. Good Luck choosing! Or Get a Galaxy S with majority of 10 Million People alone for it.
In our company we select several real devices to cover most popular screen size / gpu vendor / form factor combinations, e.g. there are 4 major GPU vendors and around 5 popular resolutions, we create table with all possible combinations and fill it according to statistics data for current period (end of spring 2014):

More about how we select test devices on our blog http://developers.nravo.com/best-test-devices-for-game-development/
You can go also in some stores like best buy, buy the device and return it when tested within a week or so. It's not very nice and fair, but it works in the US. I have actually a client that exposed his testing problems and best buy agreed that he would just test on several machines, so he could be up front about it. Try it, nothing to loose.
– Jean-Fabre