I'm a Construct 2 developer and I have created an online highscores table for my games. It's so simple, mobile adapted and let me to add the score of my players without make him to login or create an account (that's why I decided to make it my own service).
Now you can start to generate your online highscores tables in a minute. Just register on:
You only must to post to an url with the points encrypted in a different way for each game and the score appears on the page.
The user experience is good: for example, in Phonegap the highscores table appears inside the Game.