Now, this is all IMO (in my opinion).
African Dwarf Frogs are aquatic frogs that are often recommended for betta companions. Well, they can live with bettas, but will they survive. ADF's do not go for food as quickly as other fish, so they would not survive in a community tank, unless you commit to sticking your hand and tongs in the tank to feed them every day. They are also poor swimmers. A tank over 20 inches is NOT recommended as it might be too high.
The minimum tank size should be 5 gallons.
When you have an ADF, I would recommend having more than one. They are social creatures. You can hear them sing to each other as well.
The best diet for an ADF would be bloodworms.
DON'T confuse ADFs with ACF (african clawed frog). If the frog has clawed feet, then it is an ACF. ACFs can transfer fatal diseases to ADFs.
The ideal home:
The ideal habitat for an ADF would a 5 gallon tank with around 3-4 inches of water. You can have rocks that form a platform out of the water for them to crawl on. They breathe air, so they won't die when they come out of the water, but they will dry out. You can try to have a humid tank to keep them hyrdated.
Have some semi-aquatic plants in there and gravel. You now have a great home for your new ADF.
Hope I helped.