Finally

After having looked for and tried several programs, this program comes out at the top of those I know for smartphones.

I would have given it five stars had it been a package with a program such as Shredder or Fritz - but that it does not have but it is very good. It takes a bit to get used to it though.

It does however have a lot of openings that can be chosen randomly as among the users favorites. This is very good.

Yes, the program is a must for a serious chess player who relies on his smartphone.

Grandliseur about Chess Opener, v4.5