Lucky Patcher works for this app.
You can do it one of two ways. Root & Non Root.
Root Method
If you are rooted, simply install the app and
Lucky Patcher if you don't already have it.
Open
Lucky Patcher and locate Hola!VPN Tap it, Tap Open Menu Of Patches, Tap the 3rd option "Support Patch of InApp and LVL emulation"
After that only the top options need to be checked and they should already be that way. Hit "APPLY" and let LP go its thing. After that you can buy the unblock option in Hola!VPN for free.
NON ROOT
If you aren't rooted the method is still pretty close.
Install the app and LP if you don't already have it. Open LP and tap Hola! Hit "open menu of patches" then tap "create modified apk" then tap the 3rd option "APK rebuilt for InAPP..."
Top two options will already be checked, just hit "Rebuild" Let LP do it's thing.
When it's done it will give you the apps location. Remember it. Uninstall the current version of Hola!
Go to the modified apps location and install it. Run it and enjoy free
IAP.
If you need anymore help just let me know.