If you know the program names your application uses you can put this in your startup applications:
cat /<path-to-app-1>/<prog-name-1> > /dev/null
cat /<path-to-app-1>/<prog-name-2> > /dev/null
cat /<path-to-app-1>/<prog-name-3> > /dev/null
(... SNIP ...)
cat /<path-to-app-9>/<prog-name-9> > /dev/null
Additionally if your applications has large configuration files you can speed up access to them in startup applications as well using:
cat /<path-to-config1>/<config_file-1 > /dev/null
If after preseeding the caches above, you wish to clear them out and regain RAM, you can create and run this bash script:
#!/bin/bash
if [[ $(id -u) -ne 0 ]] ; then echo "Please run as root" ; exit 1 ; fi
sync; echo 1 > /proc/sys/vm/drop_caches
sync; echo 2 > /proc/sys/vm/drop_caches
sync; echo 3 > /proc/sys/vm/drop_caches