Every night before going to sleep, I always play one game of Solitaire. Since moving back to Android (from iOS) I had to do a complete relook at the options for Solitaire games. Many reviews complained about ads that could not be closed, and some reported crashes. But the most common complaint fort 'free' games were the intrusiveness of ads, some even obscuring parts of the game.
There is one game that came up as completely free without ads on Android, and that was Classic Solitaire Klondike by PotatoJam. Imagine my surprise when I started to play it, and I saw it was identical to the one I had settled on for my iPad. I double-checked, and yes, on iOS it is published by Nadzeya Roshchyna, also without ads and completely free, but it is the same game. Its rating is 4.7/5 with over 1 million installations.
The game is rock solid with a few basic options like 1 or 3 card draw, scoring/no scoring, easy play, and left or right-handed play. There is no changing of background or deck colours, etc, but it does keep stats and scores on games played (if you opt for that). So, playing on the iPad I have managed a score of 1,206. It gives a time score as well, so to achieve this result I finished the game in 01:25.
Although the game shows your play stats at the end, there is a newer feature coming (but been a long time now) for a proper statistics view, and I'm not sure if that is intended to be online. The problem with online and leader boards, is there are then some ongoing costs involved in the syncing and storage.
What is also nice for me is that the Android and iOS versions are absolutely identical, so switching between them uses the same muscle memory, but there is no syncing of results at all between the devices.
For tons of options and leader boards etc, the next best I seem to find was Solitaire - Classic Card Games by MobilityWare with a rating of 4.6/5 and 100 million downloads. Its ads were not too bad as they stayed at the type of the screen, but the paid version is subscription only (and I really avoid subscriptions if I can).
See Potato Jam