Amazing and simply essential.
When you're keeping track of a lot of games, marking them as "watched" on f95 just isn't enough, since (at the time of writing) there's no way to reliably check the latest updates among your watched games. F95Checker does just that. You open it, bam, since your last visit games A, B, C and J were updated, here's where you can download them, here's your coffee and have a nice day. Biggest timesaver ever, instead of checking hundreds of threads.
Not only that, there are several very useful sorting tools, and for each game you see the engine, the current version (and the one you have installed if they don't match), the forum score and your personal score, and the thread is just a click away. When I'm unsure what to play next, this tool is what I use to easily access information and make a decision.
Last but not least, the dev is present on the thread, always helpful, and he listens to popular demands for his updates.
For real, try it.