This guide is for Debian Stretch amd64. For i386 see notes at the end.
Warning: This is an unsafe procedure since it does not verify the package signatures. A safer way to proceed would be to add jessie to your /etc/apt/sources.list, install the packages, then remove jessie from sources.list.
Proceed at your own risk.
When making the move from Jessie do Stretch, I noticed RStudio does not start after installation. In fact, on close inspection, I realized the installation failed to meet dependencies. The debian package for RStudio available as of March 28 2016 (version 0.99.893) requires dependencies not available on Stretch (which will use a newer version).
Someone pointed out to me that these dependencies are available on Ubuntu 16, alongside the newer ones, which means they can be installed side-by-side.
I tried to download and install them manually, and it seems to solve the problem.
The following commands download and installs the dependencies as well as Rstudio 0.99.893 for amd64.
wget http://ftp.us.debian.org/debian/pool/main/g/gst-plugins-base0.10/libgstreamer-plugins-base0.10-0_0.10.36-2_amd64.deb
wget http://ftp.us.debian.org/debian/pool/main/g/gstreamer0.10/libgstreamer0.10-0_0.10.36-1.5_amd64.deb
wget https://download1.rstudio.org/rstudio-0.99.893-amd64.deb
sudo dpkg -i libgstreamer0.10-0_0.10.36-1.5_amd64.deb
sudo dpkg -i libgstreamer-plugins-base0.10-0_0.10.36-2_amd64.deb
sudo dpkg -i rstudio-0.99.893-amd64.deb
For i386 architectures, you should adjust the URLs and package names.
Find your Rstudio package here:
https://www.rstudio.com/products/rstudio/download/
And grab the appropriate dependencies from:
https://packages.debian.org/jessie/libgstreamer0.10-0
https://packages.debian.org/jessie/libgstreamer-plugins-base0.10-0