Here is a template for a letter that you could send to parents, if you think it would be useful for students to buy a subscription for this site. 

Dear parents, 

We are writing to draw you attention to a resource that we think would be really useful for your child to purchase. StudyIB.net/mathsapplications is a site explicitly for students of the Maths Applications & Interpetation SL (standard level) course and includes....

• 200+ Teaching videos covering the key concepts on the syllabus.
• 200+ Slides with visual explanations and examples.
• Hundreds of onscreen practice questions with feedback on each topic
• A questionbank with 1700+ questions with answers and explanations where you can choose a set to practice on by number of questions, topic, subtopic and difficulty level.
• Revision cards
• 100+ original exam style questions with video solutions
• Regular updates with more videos and questions going up every month.

And more.....

• You can also find a comprehensive section on how to use the  Your Graphical Display Calculator
• There is a really helpful chapter on how to consider the  IA & technology
• A  Pre-IB Preparation page to help make sure students have the foundational skills needed to access the course
• A crucial section on Exam Advice
• With a subsection on how to get  Sixes & sevens

Alongside the site is also an app that can be downloaded - it is called 'Inthinking Revision App'. where the multiple choice questions can all be found - so students can revise on the go on the phones. 

The pricing for this site is very reasonable. One month's full access is only 12 euros, and a full year is just 54 euros. Especially when comparing this to the cost of a tutor, we think this is a worthwhile investment that could make a real difference to your child's understanding and results.