1. Deezer Premium for FLAC downloads. There are public accounts out there that you can use so you don't have to pay, but I am paying so I don't have to worry about accounts expiring/getting banned as well as to use Discover and other features. Plus, it's nice to be able to pop up a song and add it to my list to be able to download later if I'm not at home.

2. Murglar for downloading files from Deezer. It's a really nice program and once you plug in your account's key, it works very seamlessly.

3. MusicBee to play audio on the PC. It looks like a lot of people still use older versions of Winamp, foobar2000, and iTunes, but I wanted something different and modern. It is actually an extremely good program and I've had no issues with it whatsoever. Would definitely recommend!

4. FreeFileSync to compare the audio files on my PC to the ones on my phone's storage. Since the phone uses MTP for file transferring, a lot of file syncing programs and such can't see it. FFS is the only one I've found that does and it works really well. Having to move everything over manually with a large library would really suck.

5. PowerAmp on my phone. This is a paid app with a free version. I don't remember what limitations the free version had that made me want to buy it, but it is worth the purchase regardless. It is an extremely powerful and elegant audio player for Android.