The ASA 5505 is a hardware switch firewall (unlike the 5510+ which are routed ports). The ASDM handles this well by visualizing "Interface" assignments to VLANs. The "Wizard" features (Startup Wizard and VPN Wizard) are excellent for junior admins, automating complex ACL and NAT generation automatically.
The "IDM" part of the launcher stands for Intrusion Detection System Manager. If your ASA 5505 has a CSC-SSM card (Content Security) or you are utilizing basic IPS features, the Launcher allows you to configure signatures. cisco asa 5505 asdm-idm launcher download
copy tftp://10.0.0.2/asdm-713.bin disk0:/asdm-713.bin
asdm image disk0:/asdm-713.bin
http 192.168.1.0 255.255.255.0 inside
write memory
Call Cisco TAC (Technical Assistance Center) and clearly state you need the ASDM-IDM Launcher for an EOL ASA 5505. TAC engineers often provide direct download links for security patches without a contract. The ASA 5505 is a hardware switch firewall