Mobile connection to my forum

[SF1NX]

A member asked me this : 

Speaking of "malware" or whatever, when I visit this site on my Android phone, sometimes I get popups asking me to download stuff to "speed up your phone" etc... one of them even tried to direct me to the google play store to download some app or other   
Doesn't happen on my phone on any other sites I visit and it doesn't happen on here every time, just sometimes...
so I'm wondering if certain ads on here might be doing it?

http://sfinxsplace.forumclan.com/forum

Can anybody give me advice on this problem ?   

[Base]

Hello,

I visited your forum on my iPhone and I did not encounter any problems like this. It sounds like adverts and nothing to be concerned about. However, I would advise the member to not click on or download anything they're not sure of.

Just to be on the safe side, could the user perhaps provide any screenshots?

[SF1NX]

Hello,

I visited your forum on my iPhone and I did not encounter any problems like this. It sounds like adverts and nothing to be concerned about. However, I would advise the member to not click on or download anything they're not sure of.

Just to be on the safe side, could the user perhaps provide any screenshots?

Thank you for checking, i'll ask him for screenshots.   
It can take while before i have them, he just left for the USA.  

[Base]

Alright, then. Do any other users experience this?