Refer Calculator Pro+ to your friends and upgrade to pro version for free.
2. Click on "REFER FRIENDS".
3. Click on the application in which you want to invite your friends.
4. Once anyone of your referral installs PSB. You will receive the message from Calculator Pro+ team with your total referral count.
6. When your 10 referrals install Calculator Pro+. You will get one-year pro version subscription for free.
7. Enjoy your Calculator Pro+ pro version application for one year.
Please mail us at "info@privatesmsbox.com" for any query.