You should first try the Demo version to determine if your device is compatible and SMSCrypt satisfies you. Notice that the prices include 3 additional device licenses for free; therefore, you can split the cost in 4 and share SMSCrypt with three persons to communicate with.

After you buy, SMSCrypt will need to be activated on your device. The activation code will be sent to you by email; so, make sure you provide a valid email address during the purchase. If you buy via Paypal, click "Return to merchant" when the transaction is completed in order to download SMSCrypt.

Product	Comparison	Demo	Price	Buy via Paypal	Get it Free
SMSCrypt Lite 2.4	Requires less powerful handsets. No additional AES algorithm. Cannot import contacts from phone. Physical access security (Login). Improved user experience.	Download Now	€2.99 EUR + 3 device licenses for free
SMSCrypt Pro 2.7	Requires more powerful handsets. Additional AES algorithm. Can import contacts from phone. Physical access security (Login). Improved user experience.	Download Now	€3.99 EUR + 3 device licenses for free

When you buy, you agree that you tried the Demo version, found it satisfactory and compatible with your device. At the same time you and not the author are totally responsible for making sure that your country or local laws allow the use of such a program.