This gets asked frequently, and the solution is pretty straightforward: Yes, you can integrate vBCredits with vBActivity, vBShop, or both.
Go into vBCredits admin and select the currency manager. From there, click the add a new currency link. On the page that loads, it will have detected the currencies from other addons for you to simply choose from a dropdown list and it will populate the form with the tech details for you. Alter any other settings as you see fit, and save it. Now your events and displays and such can operate with the points from these other addons.
* When using vBActivity, it is best to leave those actions handled under it out of vBCredits, as vBActivity cannot make it's calculations without its own logs.
* When using vBShop only, you could either import the currency into vBCredits, or pick a vBCredits currency from the currency manager and put the value from Field column into the vBShop Points Field setting - and turn off Points Accumulation while you're there.
* When using all three, you will need to chain the vBActivity currency between them, as the vBActivity currency cannot be changed. vBShop by itself can go either way (dbtech_vbactivity_points).
* Any default currencies from vBCredits can be safely deleted afterwards, but you may want to transfer the user balances first. You could also import all of the native currencies from these addons and users can manually transfer between them using the related vBCredits functions.