You're asking for art applications? There's quite a bunch.
Aside from the obvious Photoshop, you can also try:
- GIMP (free)
- Paint Tool SAI (free trial, then 5400JPY which is about $40/?30 I believe)
- OpenCanvas (free trial if you get from here, then I think $60 - you can also get this one through Steam)
The above all work nicely with graphics tablets. There's also:
- Paint.NET (free)
- Art Rage (free trial, then about $50 - also comes with mobile versions for significantly less, like $4.99, they're just less feature-rich)
Not sure how well they work with graphics tablets.