It's possible, but not very likely. If you were on an unsecured network, and someone was running a packet sniffer and collecting the data, provided the apps and web pages were unencrypted, they could figure out what you were doing.
If the wireless is not secure and the apps use the network then they can see the data from the apps. Depending on the app this data may be encrypted or not but using the destination info they may be able to deduce some of the info about what app it is if encrypted.