You’d be better off using a subdomain for each app.
app1.example.com {
root * /path/to/app1
encode gzip
try_files {path} {path}.html {path}/ /index.html
file_server
}
app2.example.com {
root * /path/to/app1
encode gzip
try_files {path} {path}.html {path}/ /index.html
file_server
}