Newifi Mini has reliable hardware(MediaTek MT7620A 580MHz, 16MB Flash, 128MB RAM, 2.4G/5G WIFI, 1 USB 2.0 port) for flashing third party firmware, but the features of official firmware is very limited, and you have to flash the firmware in order to install other software.

I tried both OpenWrt and PandoraBox, and PandoraBox's WIFI signal is much better than OpenWrt. OpenWrt works fine except the WIFI signal. So I decided to use PandoraBox, and it worked well for months without rebooting.

Flash firmware

1.Download xRouterManager.

2.Download firmware.

3.Disconnect any WIFI, and connect your computer to the router with cable.

4.Install xRouterManager and run.
Enter your router password(default password is admin) to unlock, click "Advanced recovery", and choose the firmware in step 2, click next and wait for flashing complete.

Configure the router

1.Enter http://192.168.1.1/ in the browser, username "root", password "admin".

2.Select System -> Software -> Configuration tab, and replace the text with the code below:

arch all 100
arch ramips_24kec 200
arch ralink 300
arch ramips 400`

dest root /
dest ram /tmp
lists_dir ext /var/opkg-lists
option overlay_root /overlay

src/gz r2_base http://pb.scorpwill.com/base
src/gz r2_management http://pb.scorpwill.com/management
src/gz r2_packages http://pb.scorpwill.com/packages
src/gz r2_routing http://pb.scorpwill.com/routing
src/gz r2_telephony http://pb.scorpwill.com/telephony

Install applications and configure

1.Run cmd, and telnet to the router.
telnet 192.168.1.1

Enter password "admin"

Remove old packages

opkg remove luci-app-chinadns
opkg remove ChinaDNS

Install wget and ca-certificates

opkg update
opkg install wget
opkg install ca-certificates

2.Install additional packages
Add package source in System -> Software -> Configuration

src/gz openwrt_dist https://mirror.scorpwill.com/openwrt/base/ramips
src/gz openwrt_dist_luci https://mirror.scorpwill.com/openwrt/luci

Install ChinaDNS and shadowsocks

opkg update
opkg install iptables-mod-tproxy ip ipset
opkg install ChinaDNS
opkg install luci-app-chinadns
opkg install shadowsocks-libev
opkg install luci-app-shadowsocks

3.Configure services
Select Services -> shadowsocks in your browser.

Add a server, enable Transparent Proxy and Port Transfer(port: 5300, DNS server: 8.8.8.8:53).

Enable ChinaDNS in the menu, and change upstream DNS server to: 114.114.114.114,127.0.0.1:5300

4.Select Network -> DHCP and DNS
Change DNS forwardings to ChinaDNS address(127.0.0.1#5353)

Select Resolv and Hosts Files tab, check "Ignore resolve file" and "Ignore Hosts files"

5.Configure dnsmasq
vi /etc/init.d/dnsmasq

Replace "conf-dir=/tmp/etc/dnsmasq.d" to "conf-dir=/etc/dnsmasq.d"

mkdir /etc/dnsmasq.d && cd /etc/dnsmasq.d

wget http://mirror.scorpwill.com/dnsmasq.d/bogus-nxdomain.china.conf
wget http://mirror.scorpwill.com/dnsmasq.d/adblock.conf

Restart dnsmasq
/etc/init.d/dnsmasq restart

Congratulations, you have successfully installed PandoraBox, and your network is totally free now.