Explanation of museum exhibits must give useful and adequate information to museum visitors. However, good explanation costs a lot and is hard to be maintained by museum curators. This is the case with voice and/or video guidance, or smartphone applications. To cope with the issue, this paper proposes a novel personal support aid: Stamp-On Developers Toolkit (Stamp-On/DT) for visitors, developed by the visitors themselves. Stamp-On/DT consists of smart devices with explanation contents and 'stamp' devices attached to corresponding exhibits. The unique features of Stamp-On/DT are summarized as follows: (1) the digital contents of the corresponding explanation can be created by both visitors and curators, (2) the contents are easily described with conventional web tools such as HTML, CSS, or Java script, and (3) users are only required to save exhibited images in the same exhibited location with the same names. To validate the effectiveness of Stamp-On/DT system, we have conducted a workshop in a museum to let visitors create digital contents and then we have evaluated their performance.. From the workshop experiments, we conclude that Stamp-On/DT is an effective, easy and interesting aid in understanding museum exhibits.