The first mobile seems to be by Sharp in Japanese markets. I had one Sony-Ericson camera phones back in 2004-2005 totally useless device, the Wolfenstein 3D had more photorealism and resolution. That 5110 were my first phone back in the days. There were all sorts of phone hacks* floating around between teenagers back then as always someone had family member in Nokia or phone service provider ranks.
* Phone jamming sms messages, free messages / calls from somewhere deep down from the service mode etc. etc. Funny times.
PPS. I remember from that era a one case where Nokia had a battery model that took fire in random cases. What a hell it did arise and they solved the problems. Then ten years later no-one seems to care that Iphones et al were catching fire in normal use.