Macbook Pro OS X Version Questions

I just bought a Macbook pro from a friend to use as a backup and alternate computer for both personal and work. As i have been working on upgrading things I have ran into a couple of apps that are not longer compatible with the version of OS X I am currently using.

My question is what is the latest OS X version that i can have on this computer seeing it as an older computer. While reading online it seems that it is compatible with Yosemite but upon installing it, I am told it isn't compatible. With the specs i have below, what version is the latest that i can update to and if I am at my max is there a way that I can get older compatible versions of apps from the store, or elsewhere for that matter?

My system specs are:

Macbook Pro 13-Inch Mid 2007 version

2.16 GHz Intel Core 2 Duo

3 GB 667 MHz DDR2 SDRAM

Intel GMA 950 64 MB Graphics

Mac OS X Lion 10.7.5 (11G63)

Fully up to date according to system update tool

Please point me in the right direction as to information regarding if i can go any higher in OS X as well as finding compatible app store software if I am unable to upgrade any further.

Thanks for reading and your time