Use of apps for GPS curse

Can anyone answer the question, can you use an app that you enter the club driving length of every club in your bag. Then when he plays he can read the correct club to use. From a point on the course. I am being informed that the club selection cannot be used in competition. Is this true?

Can you not just remember? It's only a matter of adding around 10 yards every time?

Smartphone app = competition illegal.

Or you could just write the distance you hit each on the club. But seriously, do you really need something like that, can't you just use your eyes and feel? I must admit my yardages have gone a bit to pot since I've been testing the superb Golf Buddy Platinum GPS () and am beginning to realise just how inconsistent I am with yardages - not that I don't hit the greens or anything but I do constantly overide the yardages in my head. F'rinstance, at a local course they have a par 3 that plays anywhere between 175 to 190. I can honestly say that over the years I've probably used a driver, 3 wood, 18 & 21 deg hybrid, 4, 5, & 6 irons and reached the green with them all - it just depends on wind, humidity, heat and even what ball I'm using.

I use GPS on my phone (obviously not in comps) but when i first got i was using it on every shot. I found it became a hindrance as I was relying on it. Now it is used only for plotting my way round new courses where I'm finding 'interesting' spots on the golf course and to see how accurate the fairway yard markers are. The rest comes down to the conditions on the day and feel.

Most of you will have seen it but a good article here on the rules of golf and distance measuring devices

http://www.golfshake.com/improve/view/4121/Distance_Measuring_Devices_DMDs_e_The_Facts.html