What is the Pyramid Solitaire game, how does it work?

According to the introduction of Melele, Pyramid Solitaire is a Card game on the Android platform. There is currently a 1.02 version released on Jan 10, 2018, you can see the details below.

PYRAMID SOLITAIRE

Main characteristics:
- Play different Pyramid variants: 7 rows, 6 rows + 6 wildcards, 7 rows + 7 wildcards
- It includes help and play explanation
- Settings: Cards size, cards back color, sound, scoreboards, table color,...
- Scores: Matches, times, more and fewer movements, total points,...
- Achievements: They allow to achieve experiencie points
- Save and load game
- Unlimited undo
- Landscape and vertical orientation
- Move to SD

Play:
- The aim of the game is to remove all the cards from a pyramid
- Pairs of exposed cards can be removed if their values total 13

Scoring Pyramid Solitaire:
- Points are won by removing cards. If all cards from a row are removed, there is a bonus

The rules settings allow changing some of this rules:
- Game end: Remove all the cards or only pyramid cards
- Stock redeals: one, three or unlimited
- Extra cell
- Allow remove a pyramid card with a card covered by the first
- Stock card avaliable or not
- Allow undo

Other Melele games: Gin Rummy, Hearts, Sevens, Oh Hell, Crazy Eights, Solitaire (Klondike), Spanish Solitaire...

Minor improvements and corrections