I had something like 3800 words for review yesterday evening but this morning it's gone done to 900. My online account still says I have 3900 to review but my app just will not sync to that at all. It syncs and I'm studying all lists but the number is wrong.

Any ideas about how to solve this?

it all depends on how quickly you add new words and how well you remember them.

If there is a really huge number I would hit the "save me" button in "my words".

another option is not to be too impressed with the numbers of reviews and slowly do as much as you can do.

I now have found a balance for myself. my average number of reviews when I open skritter is around 1500. after two hours of skritter it is down to 900 or so.
then I add some words manually.

enjoy!

If you click on sync status, you can force the app to check with the servers and this should correct any discrepancy online and with the app.

I have no problem with the large number, and that's not my problem. Like I said, the number of words it says I have for review is incorrect and not the same as what it says on my online account.

Try doing a "Clear Local Data" from within your app's account settings in order to get a fresh copy from the server and clear up any problems with your device's local copy of the data.