Things to keep in mind before developing a blackberry application

I have just entered into the Blackberry Arena.

Now I am ready for the develop an application for the blackberry devices.

(1) But I would like to know that while I develop any app for blackberry, then should I tar开发者_运维知识库get some fix devices ?

Or else which are the things that I should keep in mind while developing any new blackberry app ?

(2) Another thing I would like to know is like I have seen somewhere that I need to purchase a developer device for testing the app on a real device ... is it so ?

And if it the case then which device I should purchase so that I can test most of the app features in the device..

Thanks in advance...

May be helpful:
What is the best practise in blackberry development for reaching the widest range of smart phones?
BlackBerry use of the simulators
Blackberry User Interface Design - Customizable UI?

Talking about blackberry developer device, I think that could be at least two models: with trackball (say, Bold) and with touchscreen+accelerometer (Storm)
If you choose Storm2 as a suggested dev phone by RIM you will be able to use RIM OS 5.0.0 with new UI, Google Gears and SQLite, but 5.0.0 is available for Storm and Bold to upgrade anyway.

That would be really great if RIM would provide developers with some special versions devices (better debugging, console data management, maybe bootstrap), but there is no such.

1. portability is a big issue in blackberry development.

   a.blackberry is forward compatible means if you compile code in 4.5 os, if will work on devices with "device os">=4.5 but it will not work on devices with "device os"<4.5.

   b.keyboard layout: if you are using blackberry provided ui components, it will manage automatically all key board layout but if you are directly dealing with keyboard you have to take care of this.

   c.Radios(CDMA,GSM,WIFI,etc):you have to take care of that target device is using cdma or GSM. e.g. if you use

   SIMCardInfo.getIMSI()

in cdma device, you will get UnsupportedOperationException.

d.screen size: here is the different screen size of blackberry devices.

2. Don't rely on simulator always test on device. you can find many questions on forums like "bla bla working on simulator but not working on real device" 3.For testing on device, cod signing is required that cost $20.

here is the details of cod signing.

There are many things that you will learn through experience and than share with us.