Hi HonzaZ,
Installed Avast WiFi Finder on an Android with KittyKat 4.1 and somehow the continued action of it gave the Smartphone a light fewerish brush and extended temp. Did not like to stop it, because of expected errors, but had to cool my peripheral down. It happened just after boosting my Android.
This was only at a single occasion and hick-up, furthermore I like to mention I like this Avast WiFi Finder quite a lot. 
Damian