How could i get a personalized app made for my SGS3??

[snafubaby]

I have a SGS3, but this app i have in mind could be used on any Android phone. It's just an app for my job. Are there people/companies out there that will make personalized apps? How much does it usually cost? I want a simple app that is a timer, and it counts down from 5 minutes to zero. THEN, when it reaches zero, a synthesized voice will say "your 5 minutes are up." over and over, until i press a STOP button located somewhere on the screen. While that voice is saying "your 5 minutes are up.", it's counting the minutes until i press the STOP button. So, let's say i use the app, and it counts down to zero, and then says "your 5 minutes are up.", and i don't press the STOP button for 10 minutes, 25 seconds. Then i press it, and on the screen, it says "10:25". Does anyone know of a company, or a person, who would write such an app? Please let me know. Thanks!